Vince Cable: ‘If we are to avoid action from Brussels, we must continue to demonstrate that our voluntary approach is working.’ Photograph: Anthony Devlin/PA

Vince Cable has raised the spectre of Europe imposing mandatory quotas on the number of female directors in British boardrooms, as he pushes for Britain’s largest businesses to swiftly appoint more women to senior positions.

The business secretary, who has long opposed compulsory quotas for women in the boardroom, made the comments as he lauded the FTSE 100 companies that had made most progress since the launch of Mervyn Davies’s report in 2011.

Lord Davies set a target of 25% of FTSE directors to be female by 2015, with the most recent statistics in October putting the score at 22.8%.

Cable said: “Our target of 25% women on boards by 2015 is in sight. However, the threat of EU mandatory targets remains a reality if we do not meet it.

“If we are to avoid action from Brussels, we must continue to demonstrate that our voluntary approach is the right one and is working.”

In a letter last month to Sir William Cash, chairman of the European select committee, Cable warned that progress on hiring female directors had slowed as he updated the committee on a draft European directive, which currently proposes women filling 40% of non-executive roles and 33% of executive positions by 2020.

“If the directive as currently drafted was agreed, we would almost certainly need to extend or adapt our domestic policy in order to try and reach [targets qualifying the UK for an exemption],” Cable said.

“This is because the scope of the directive as currently drafted covers a wider group of companies than FTSE 100/250, on which UK domestic policy has focused.”

The picture among slightly smaller companies listed in the FTSE 250 is significantly worse – only 17.4% of directors there are female, according to the latest official figures.

Davies said: “In 2011, British business said they could fix this problem on their own, and I am delighted we are now seeing evidence of this, with more women being picked to serve on the boards of Britain’s biggest companies.

“However, the job is not yet done. Strengthening the executive talent pipeline remains the next and longer-term challenge.”

The 10 companies making most progress by percentage point gain since the launch of the Davies report are Old Mutual, Aggreko, GlaxoSmithKline, Wolseley, Land Securities Group, Associated British Foods, Capita, Petrofac, Weir Group and HSBC.

Six of those started the process with no women on their boards at all, while neither of the two companies improving by the largest margins – Old Mutual up 38.5 percentage points and Aggreko up 30 points – had any female directors at the launch of Davies in 2011.

Three firms in the top 10 improvers – Associated British Foods, Petrofac and Weir Group – still need extra female directors for the 25% threshold.